High-performance chromite by structure stabilization treatment

• Published in: Journal of iron and steel research, international Vol. 27; no. 2; pp. 169 - 179
• Main Authors: Wang, En-hui, Luo, Chang, Chen, Jun-hong, Hou, Xin-mei
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.02.2020
• Subjects: Applied and Technical Physics; Engineering; Machines; Manufacturing; Materials Engineering; Materials Science; Metallic Materials; Original Paper; Physical Chemistry; Processes; Corrosion resistance; Refractory; Chromite; Structure optimization
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1007/s42243-019-00354-3

Chromite is an important raw material applied in refractories. Efforts have been made to obtain high-performance chromite by adding MgO and Al 2 O 3 from the viewpoint of structure optimization. In order to explore the effect of Al 2 O 3 and MgO on the structure, two formulas, i.e., Mg-rich and Al-rich ones, were selected. The phase and microstructure development of samples heated in the temperature range of 1200–1600 °C were studied by X-ray diffraction and scanning electron microscopy with energy-dispersive spectrometry. MgO and Al 2 O 3 added have diffused into chromite successfully by heat treatment. MgO diffuses into chromite, occupying the tetrahedral vacancies caused by the diffusion and oxidation of Fe 2+ ions to stabilize the structure. Al 2 O 3 diffuses into the surface layer of chromite, forming spinel-sesquioxide structure. Al-rich sample which has spinel-sesquioxide structure shows better corrosion resistance toward fayalite slag than Mg-rich sample which has single spinel structure by blocking the interdiffusion between Fe 2+ ions in fayalite slag and Mg 2+ ions in chromite.